1. Field of the Description
The present invention relates, in general, to fabrication of three dimensional (3D) objects, and, more particularly, to a filament-based 3D printer and corresponding printing materials (e.g., filaments) specially configured and operable to print 3D objects that are configured to provide protection against 3D scanning (e.g., to prevent full or effective scanning of the objects printed with a 3D printer).
2. Relevant Background
3D printing is an additive technology in which objects (or “printed 3D objects”) are created from a digital file. The digital file may be generated from software such as a computer aided design (CAD) program or another 3D modeling program or with a 3D scanner to copy an existing object that provides input to a 3D modeling program. To prepare the digital file for printing, software, provided on a printer-interfacing computer or running on the 3D printer itself, slices the 3D model into hundreds to thousands of horizontal layers. Typically, only the outer wall or “shell” is printed to be solid such that a shell thickness may be defined as part of modifying the 3D model for use in printing, and, during printing, the shell is printed as a solid element while the interior portions of the 3D object are printed in a honeycomb or other infill design (e.g., to reduce the amount of material that has to be printed to provide the printed 3D object).
When the prepared digital file of the 3D object is uploaded into the 3D printer, the 3D printer creates the object layer-by-layer. The 3D printer reads every slice (or 2D image) from the 3D model and proceeds to create the 3D object by laying down (or printing) successive layers of material until the entire object is created. Each of these layers can be seen as a thinly sliced horizontal cross section of the eventually completed or printed 3D object.
One of the more common 3D printer technologies uses fused deposition modeling (FDM) or, more generally, fused filament fabrication (FFF). FDM printers work by using a plastic filament (e.g., acrylonitrile butadiene styrene (ABS) or polylactic acid (PLA) provided as strands of filament that is 1 to 3 millimeters in diameter) that is unwound from a coil or spool mounted onto the printer housing. The plastic filament is used to supply material to a print head with an extrusion nozzle, e.g., a gear pulls the filament off the spool and into the extrusion nozzle. The extrusion nozzle is adapted to turn its flow on and off. The extrusion nozzle (or an upstream portion of the print head) is heated to melt the plastic filament as it is passed into, or through, the extrusion nozzle so that it liquefies. The pointed extrusion nozzle deposits the liquefied material in ultra fine lines (e.g., in lines that are about 0.1 millimeters across).
The extrusion head and its outlet are moved in both horizontal and vertical directions to complete or print each layer of the 3D model by a numerically controlled mechanism that is operated or controlled by control software running on the 3D printer (e.g., a computer-aided manufacturing (CAM) software package adapted for use with the 3D printer). The extruded melted or liquefied material quickly solidifies to form a layer (and to seal together layers of the 3D object), and the extrusion nozzle is then moved vertically prior to starting printing of the next layer. This process is repeated until all layers of the 3D object have been printed.
As mentioned above, a 3D object that has been printed on a 3D printer or otherwise fabricated is relatively easy to copy through the use of 3D scanner and a 3D printer using the files created by the 3D scanner. There are many commercially-available scanners that can reproduce a digital model that may be used as the digital file used to control printing by a 3D printer. As a result, a person with a 3D printer may copy nearly any 3D object even without access to the digital file originally used by a manufacturer in creating the “original” 3D object, and it can be difficult for a company distributing collectables and other 3D objects, such as plastic figurines of movie and animated film characters, to prevent unlicensed copying. This can be an even larger problem for companies that want to protect products that are made through a 3D printing process. These products or items are often designed to be well suited for fabricating using 3D printers such as through the design of their exterior surfaces, but the 3D objects may have unique features or have associated intellectual property features that the companies wish to protect by limiting copying.
Hence, there remains a need for new 3D printers or printing methods that make it difficult to copy a 3D object, such as one printed with a 3D printer. Preferably, such 3D printers and printing methods would be adapted to be relatively inexpensive to implement and would be useful with existing and future 3D printer technologies such as with fused deposition modeling (FDM) or fused filament fabrication (FFF) technologies.